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Article Reference Esperiopsis koltuni sp. nov. (Demospongiae: Poecilosclerida: Esperiopsidae), a carnivorous sponge from deep water of the Sea of Okhotsk (North Pacific)
Esperiopsis koltuni, a new species of the sponge family Esperiopsidae, is described from deep water of the Sea of Okhotsk. The new species has a unique growth form: there is a basal plate with radiating cylindrical branches, whose oval flat distal parts bear filament-like outgrowths. Megascleres are arranged differently in the main part of branches and in their distal flat parts. The dermal membrane contains isochelae with protruding alae and abundant sigmancistras. Microscleres are represented by large anchorate spatuliferous isochelae, small isochelae, sigmas and sigmancistras. Esperiopsis koltuni sp. nov. is hermaphroditic, with parenchymella larva. The larval skeleton consists only of sigmas and sigmancistras. Esperiopsis koltuni sp. nov. can be easily distinguished from other Esperiopsis species by dimensions and combination of spicule types. In particular, it is the only species in the genus with three different size categories of styles. The new species lacks the aquiferous system, has a characteristic body plan with symmetrical lateral expansions, an unusual arrangement of microscleres in the dermal membrane and true sigmancistras. Moreover, prey capture by a filament-like outgrowth of the flat distal part was observed. All of these characteristics indicate that Esperiopsis koltuni sp. nov. is a carnivorous sponge.
Located in Library / RBINS Staff Publications
Article Reference Local extinction processes rather than edge effects affect ground beetle assemblages from fragmented and urbanized old beech forests.
Located in Library / RBINS Staff Publications
Article Reference Flow cytometric sexing of spider sperm reveals an equal sperm production ratio in a female biased species.
Located in Library / RBINS Staff Publications
Article Reference Endosymbiont induced sex-ratio distortion in the dwarf spider Oedothorax retusus.
Located in Library / RBINS Staff Publications
Article Reference Return to sender: Hydrozoa collected by Emperor Hirohito of Japan in the 1930s and studied in Brussels
A small number of Hydrozoa specimens, collected by Emperor Hirohito of Japan in Sagami Bay in the 1930s, was re-discovered in the Royal Belgian Institute of Natural Sciences in Brussels. The history of the collection is described here; part of it has been returned to the Showa Memorial Institute in Japan., Een klein aantal Hydrozoa specimens ingezameld door de Japanse Keizer Hirohito in de Baai van Sagami in de jaren 1930 werd gevonden op de schappen van het Koninklijk Belgisch Instituut voor Natuurwetenschappen in Brussel. De geschiedenis van de collectie wordt hier beschreven; een deel ervan werd teruggestuurd naar het Showa Herdenkingsinstituut in Japan.
Located in Library / RBINS Staff Publications
Article Reference Middle and uppermost Famennian (Upper Devonian) bryozoans from southern Belgium
Located in Library / RBINS Staff Publications
Article Reference Rediscovery of the forgotten de Ryckholt Collection (gastropods, bivalves, worms; Late Cretaceous, Belgium)
A significant part of the collection of mid- and Late Cretaceous (Cenomanian, Campanian and Maastrichtian) gastropods, bivalves and worms described and/or illustrated by de Ryckholt in his seminal work Mélanges paléontologiques between 1854 and 1862, has recently been retraced in the historical collections at Liège University. Of the original collection, more than 206 specimens, including 196 nominal types (lectotypes and genotypes), all considered lost, are now available. The genotypes of the gastropod genera Tudicula de Ryckholt, 1862a and Prosopostoma de Ryckholt, 1862a are photographically illustrated for the first time. Prosopostoma bucculans, from the Cenomanian Bernissart Formation (formerly ‘Tourtia de Tournai’), is here chosen as the type species of the genus Prosopostoma, a possible stromboid. We also reassess the stratigraphic age of the type localities under the revised stratigraphic framework of Belgium and a detailed account on the research history of this material, in order to provide a thorough scientific background for future study of this formidable collection.
Located in Library / RBINS Staff Publications
Article Reference A new record of Notocetus vanbenedeni (Squalodelphinidae, Odontoceti, Cetacea) from the early Miocene of Peru
Located in Library / RBINS Staff Publications
Article Reference Biostratigraphic significance of brachiopods near the Devonian–Carboniferous boundary
The biostratigraphic significance of selected uppermost Famennian (Upper Devonian) and lower Tournaisian (Mississippian) brachiopod genera, belonging to the orders Rhynchonellida (e.g. Araratella), Spiriferida (e.g. Sphenospira, Prospira), Spiriferinida (Syringothyris) and Productida (except Chonetidina), is discussed. Owing to the difficulties of identifying productidine and strophalosiidine genera, in contrast to rhynchonellides and spiriferides, the biostratigraphic potential of the former has generally been overlooked. Brachiopods flourished in neritic environments that were unfavourable for conodonts and ammonoids. In the absence of the latter traditional marker fossils, they are potentially important for locating the Devonian–Carboniferous boundary in shallow water depositional settings in conjunction with rugose corals and foraminifers. On a worldwide scale, further work is required to reach a better assessment of the aftermath of the Hangenberg biological Crisis on brachiopods, notably in revising the faunas from the classical areas of the Famennian and Tournaisian stages in Western Europe.
Located in Library / RBINS Staff Publications
Article Reference Dispersal mechanisms in amphipods: A case study of Jassa herdmani (Crustacea, Amphipoda) in the North Sea
Jassa herdmani (Walker 1893), a tube-building amphipod typical of hard substrates, was found in large densities on shipwrecks from the Belgian part of the North Sea, in association with the hydrozoan Tubularia indivisa. In this area, shipwrecks only represent the source of hard substrates in an environment dominated by soft sediments. Nevertheless, the long-distance dispersal of Jassa species has never been investigated. Therefore, we tested the hypothesis of dispersal with currents, by investigating the behaviour of J. herdmani in the laboratory. Size distribution revealed that newly released juveniles (1 mm) predominated throughout the year and the lower frequency of the size class 1-3 mm indicates a high mortality or a dispersal at this life stage. Individuals of J. herdmani may initiate actively the transport by tidal or surface currents by swimming to the surface of the water or by floating at the surface, as suggested by behaviours noted in the laboratory. The reaction of the amphipods to a current was investigated in the laboratory. We could not detect any sexual function associated with drifting and there was also no preponderance of a size class in the drifting individuals. When testing different substrates, we observed a significant influence of the substrate type on the frequency at which drifting occurred: J. herdmani showed a better adherence on T. indivisa compared to other substrates. Finally, the amphipod showed also a preference for its host compared to other substrates, which suggests a possible detection mechanism. © 2007 Springer-Verlag.
Located in Library / RBINS Staff Publications